1,1

Bernhard Helmes, Prime sieving on the polynomial f(n)=2n^2-1.

l = 0; p = 2; c = {}; a = {}; Do[k = p x^2 - 1; b = Divisors[k]; Do[If[PrimeQ[b[[n]]], AppendTo[a, b[[n]]]], {n, 1, Length[b]}]; If[N[Log[x]/Log[10]] == Round[N[Log[x]/Log[10]]], a = Union[a]; l = Length[a]; Print[l]; AppendTo[c, l]], {x, 1, 10000}]; c (*Artur Jasinski*)

Cf. A143835.

Sequence in context: A039939 A199907 A264710 * A130591 A166483 A048665

Adjacent sequences: A143865 A143866 A143867 * A143869 A143870 A143871

Artur Jasinski, Sep 04 2008

Fixed broken link and corrected terms to agree with website - Ray Chandler, Jun 30 2015

approved